The Nanning Intermediate People's Court in southern China accepted the case against Phan "Sandy" Phan-Gillis on July 11, and no date has been set yet for a hearing, said a court official who gave only her surname, Chen.

Authorities detained the international business consultant in March 2015 when she visited China as part of an American trade delegation that was promoting business opportunities in her hometown of Houston, Texas.

Phan-Gillis' husband, Jeff Gillis, said Monday that her lawyer received the indictment "weeks after it was issued to the court."

He said in a statement that she is charged with being a spy for a foreign government from 1996 to 1998, and that the charges are "absolutely false."

Spying convictions carry a maximum sentence of life imprisonment.

A U.N. panel ruled in June that China was arbitrarily detaining Phan-Gillis, 56, in violation of international human rights norms because she hadn't been brought before judicial authorities or given access to legal assistance.